Optical illusion

A crust formed atop the sand, presumably from being wet, then the wind broke through in places and excavated the sand. To my eye, this is a persistent optical illusion. The deeper orange areas can be seen either as depressions (the correct view) or as low mounds, which makes it hard to make sense of the image. The latter viewpoint is especially prevalent at the right side of the image. This was close to a steep bank, and the light is mostly coming from the left.

 

Also, it's a cool if ephemeral scene.

Done